yeroc
Extracting All Items of List Inside Map
Hello all!
A bit stumped on interpreting how to parse and extract my desired data from an API’s response with HTTPoison and Poison. I think I’m missing something simple.
Let’s say I want all the applicant names from “https://data.sfgov.org/resource/jjew-r69b.json?” .
In IEx-
iex(1)> res = HTTPoison.get! "https://data.sfgov.org/resource/jjew-r69b.json?"
%HTTPoison.Response{
body: "[{\"dayorder\":\"3\",\"dayofweekstr\":\"Wednesday\",\"starttime\":\"1PM\",\"endtime\":\"3PM\",\"permit\":\"19MFF-00079\",\"location\":\"1377 FELL ST\",\"locationdesc\":\"1:05pm-3:00pm\",\"optionaltext\":\"Cold Truck: Pre-packaged sandwiches, snacks, fruit, various beverages\"...
iex(2)> body = Poison.decode! res.body, keys: :atoms
%{
addr_date_create: "2017-07-31T15:11:15.000",
addr_date_modified: "2017-08-01T10:49:12.000",
applicant: "Bonito Poke",
block: "3736",
cnn: "107000",
coldtruck: "N",
dayofweekstr: "Wednesday",
dayorder: "3",...
iex(3)> (hd body).applicant
"Liang Bai Ping"
As you can see from the JSON in the link, this is indeed the head, coming back to me in a string as I want after a bit of manipulation through HTTPoison and Poison. How would I go about calling and returning all of the heads and not just the head or tail?
Enum.map gives me nil
iex(4)> Enum.map(body, & &1["applicant"])
[nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil,
nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil,
nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil,
nil, nil, ...]
Thanks for any help ![]()
Trending in Questions
Hello!
Suppose you are building workflow (order / task / payment) processing system with the following requirements:
Each workflow con...
New
I’m in search of an Elixir library that offers PDF generation capabilities similar to Ruby’s Prawn. While there have been discussions abo...
New
I’m looking to build a personal workflow to quickly deploy web applications written in elixir/phoenix, for local consumption (ie not on t...
New
Using Phoenix.LiveView.TagEngine as an EEx.Engine is deprecated!
To compile HEEx, use Phoenix.LiveView.TagEngine.compile/2 instead.
Sta...
New
Before I dive in myself, did anyone successfully sprinkle Hologram into their existing LiveView app?
Looking for hints regarding:
Addi...
New
Hi all, I wanted to ask how the community is dealing with post-release steps.
Today we have Ecto migrations, which make sure that the db...
New
I am using Oban and occasionally, shortly after a deployment, a handful of jobs can fail because of dependency on other parts of the syst...
New
Other Trending Topics
Hey, I’m Jesse and I’m the main contributor behind Dexter, a full-featured, lightning-fast Elixir LSP optimized for large codebases. It s...
New
Beam Bots (or just BB for short) is a framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns. ...
New
Hello everyone. After busy few months I am happy to announce v0.1.0 of Emerge & Solve.
They are GUI (Emerge) and State management (S...
New
Emily is an Elixir library that runs Nx computations on Apple’s MLX. Install it as the default Nx backend and Nx, defn, Axon, Nx.Serving,...
New
I just stumbled on a newly redesigned elixir-lang.org. :tada: It looks like @Software_Mansion did the work, and I think it is generally a...
New
@hugobarauna and I (Alex Koutmos) have been hard at work on writing a book on Nerves that takes you from simply blinking LEDs to building...
New
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #elixirconf-us
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #hex
- #performance










First 5 of 5 Posts
cloudytoday
In your Poison.decode! call you’re specifying
keys: :atomswhich constructs the resulting maps’ keys as atoms and not strings, but in yourmapcall you’re providing a function which retrieves the field as it was a string (& &1[“applicant”]). I would recommend removing thekeys: :atomsfrom the Poison.decode! call. Alternatively, you can do the same but with& &1.applicant.yeroc
Ah yes! I got a bit turned around in the layers of changing the data. Thank you! Not sure what you mean by
?
cloudytoday
Oh I just meant that the alternative solution, if, for some reason, you really need them as atoms, would be to keep the
keys: :atomsin the Poison call, and to just change the function in theEnum.mapcall so that it retrieves the atoms viamap.atom_fieldsyntax (it’s equivalent to some_map[:atom_key]). And if you don’t need them as atoms, then you can simply remove thekeys: :atomsfrom the Poison call.yeroc
Ah yes! Thanks for clarifying!
yeroc
@cloudytoday Related to this question, if you have any thoughts and care to share